Are ultra-processed foods a public health hazard?

Ultra-processed foods are a major public-health question — I'll gather the latest evidence on their risks.

Yes, the growing scientific consensus is that high consumption of ultra-processed foods (UPFs) is a public health hazard, although there is active debate about the degree, mechanisms, and whether all UPFs are equally harmful.

1. What are UPFs?

There is no single universally accepted definition, but research commonly uses the NOVA system.

•NOVA defines ultra-processed foods to be "industrial formulations with five or more ingredients" that contain substances that aren't typically used in culinary preparations.

•More fully, ultra-processed foods, including packaged baked goods and snacks, fizzy drinks, sugary cereals, and ready-to-eat or heat products, undergo multiple industrial processes and often contain colours, emulsifiers, flavours, and other additives. These products also tend to be high in added sugar, fat, and/or salt, but are low in vitamins and fibre.

Examples include instant noodles, packaged snacks (e.g., chips, cookies), processed meats (e.g., hot dogs, burgers, chicken nuggets), instant soups, breakfast cereals and bars, soft drinks, ice cream, margarine, candy, sauces, and energy drinks.

2. How prevalent are they?

Exposure is very high in many countries:

•It is estimated that 70% of the US food supply is comprised of ultra-processed foods (UPFs), 55% of calories from people aged 1 and older in the U.S. are from UPFs, and 60% of children's calories come from UPFs.

•UPFs already make up more than half of the total dietary energy consumed in high-income countries, such as the US, Canada, and the UK, and between one-fifth and one-third of total dietary energy in middle-income countries such as Brazil, Mexico, and Chile.

•They can account for up to 58% of total daily energy intake in some high income countries.

3. Evidence linking UPFs to adverse health outcomes

Researchers have found links between the consumption of ultra-processed foods (UPFs) and a range of negative health outcomes, including obesity, cancer, heart disease, type 2 diabetes, and mental disorders, as well as an increased risk of death.

The most comprehensive synthesis to date is a 2024 umbrella review published in The BMJ:

•Researchers carried out an umbrella review of 45 distinct pooled meta-analyses from 14 review articles associating ultra-processed foods with adverse health outcomes.

•The review articles involved almost 10 million participants. None were funded by companies involved in the production of ultra-processed foods.

•Overall, the results show that higher exposure to ultra-processed foods was consistently associated with an increased risk of 32 adverse health outcomes.

•Consistent evidence shows that higher exposure to ultra-processed foods is associated with an increased risk of 32 damaging health outcomes including cancer, major heart and lung conditions, mental health disorders, and early death.

Specific risk estimates reported:

•Convincing evidence showed that higher ultra-processed food intake was associated with around a 50% increased risk of cardiovascular disease related death, a 48-53% higher risk of anxiety and common mental disorders, and a 12% greater risk of type 2 diabetes.

•A 2024 review from the British Medical Journal (BMJ) of 45 metanalyses, covering nearly 10 million study participants, found “convincing” evidence that a diet high in UPFs increases the risk of death from cardiovascular disease by 50% and the risk of anxiety by 48%. It found “highly suggestive” evidence that greater consumption increases the risk of death from heart disease by 66%, the risk of obesity by 55%, sleep disorders by 41%, Type 2 diabetes by 40%, early death from any cause by 21%, and depression by 20%.

•Highly suggestive evidence also indicated that higher ultra-processed food intake was associated with a 21% greater risk of death from any cause, a 40-66% increased risk of heart disease related death, obesity, type 2 diabetes, and sleep problems, and a 22% increased risk of depression.

•In another summary, eating a lot of ultra processed foods was associated with higher risks of cardiovascular events (24%), cancer (12%), obesity/overweight (23%), metabolic syndrome/diabetes (24%), depression/anxiety (27%), digestive diseases (31%), high blood pressure (11%) and death from any cause (18%).

The authors concluded: “These findings support urgent mechanistic research and public health actions that seek to target and minimise ultra-processed food consumption for improved population health.”

4. Proposed mechanisms

The causes of specific health effects are still being studied, but they are likely to occur because UPFs often have high amounts of added sugar, sodium, and saturated fat, and low amounts of fiber, vitamins, and minerals.

Review articles list multiple pathways:

•The mechanisms by which UPFs may cause harm include (1) increased total energy intake due to increased portion sizes and high caloric density, (2) increased glycemic response, (3) associated higher salt, sugar, and saturated fats that have been studied extensively, (4) additives that likely affect the gut microbiota and associated metabolism

•Nutrient imbalance, gut microbiome disruption: additives and altered textures starve healthy bacteria, favor inflammation, and weaken gut lining

•Contaminants and additives: Emulsifiers, artificial colors, preservatives can alter metabolism, induce inflammation

•Disrupted food matrices and excessive energy density that accelerate eating and increase energy intake; engineered hyper-palatable formulations that override satiety; additives (e.g., emulsifiers and non-sugar sweeteners) linked to gut and metabolic dysfunction

•Evidence suggests additives like emulsifiers and thickeners may actively harm the gut by thinning its protective mucus layer, increasing permeability ("leaky gut") and promoting a pro-inflammatory microbiome

A clinical trial cited by experts also shows people who consume a diet high in ultra-processed foods tend to overeat and gain unwanted weight.

5. Nuance and limitations

Most major reviewers acknowledge limitations and nuance:

•The researchers acknowledge that umbrella reviews can only provide high-level overviews and they can’t rule out the possibility that other unmeasured factors and variations in assessing ultra-processed food intake may have influenced their results.

•A growing critique is that not all UPFs are equal. This paper underscores that not all ultra-processed foods (UPFs) are created equal, and grouping them together as universally detrimental is overly simplistic.

•For instance, packaged whole grain breads, plant-based milks and some yogurts are considered ultra-processed, but they can be beneficial for health.

•Fortified cereals, for instance, have been instrumental in reducing the incidence of neural tube defects in infants due to the added folic acid.

•Yogurt is technically an ultra-processed food, but it can offer health benefits when low in added sugars. Yogurt fortified with probiotics supports gut health.

•One analysis found once nutrients and perceptions were factored in, the UPF classification explained only 2–4% of overeating behavior, suggesting nutrients matter more than processing per se.

•As Harvard researchers summarized: While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful.

The World Health Organization (WHO) reflects this nuance. While WHO states that Foods high in unhealthy fats, free sugars and sodium should be limited, a report from the WHO's International Agency for Research on Cancer has also suggested that processed foods such as bread and cereal reduce the risk of multiple long-term conditions – multimorbidity – due to their fibre content.

6. Public health response

Because reformulation does not eliminate harm, and profitability discourages manufacturers from switching to make nutritious foods, public policies and action on ultra-processed foods are considered essential.

Proposed measures include front-of-pack labels, restricting advertising and prohibiting sales in or near schools and hospitals, and fiscal and other measures that make unprocessed or minimally processed foods and freshly prepared meals as accessible and available as, and cheaper than, ultra-processed foods.

A linked BMJ editorial argued it is now time for United Nations agencies, with member states, to develop and implement a framework convention on ultra-processed foods similar to the framework on tobacco.

Internationally, the World Health Organization (WHO) is developing its first guideline on ultra-processed food consumption, with recommendations expected in late 2026 or 2027.

Bottom line

In epidemiological terms, high dietary exposure to UPFs — particularly sugary drinks, processed meats, salty snacks, and other formulations high in sugar, salt, saturated fat and additives — is consistently associated with obesity, cardiometabolic disease, mental health disorders, and premature mortality, supporting classification as a public health hazard at the population level. However, the NOVA category is broad and includes some nutrient-dense, fortified foods that are not linked to harm and may be beneficial, so public health guidance increasingly emphasizes dietary patterns and nutritional quality rather than demonizing every item labeled "ultra-processed."

This information is for educational purposes and not medical advice. If you are concerned about your diet, consult a healthcare professional or registered dietitian.

Citations (3)

1bmjgroup.comAcademic
Consistent evidence links ultra-processed food to over 30 damaging health outcomes - BMJ Group
Backs: “NOVA defines ultra-processed foods to be "industrial formulations with five or more ingredients" that contain substances that aren't typically used in culinary preparations. More fully, ultra-processed foods, including packaged baked goods and snacks, fizzy drinks, sugary cereals, and ready-to-eat or heat products,…”
2ansi.orgNot yet classified
Health Risks of Ultra-Processed Foods & Food Safety
Backs: “More fully, ultra-processed foods, including packaged baked goods and snacks, fizzy drinks, sugary cereals, and ready-to-eat or heat products, undergo multiple industrial processes and often contain colours, emulsifiers, flavours, and other additives. These products also tend to be high in added sugar, fat, and/or…”
3medicalnewstoday.comCommercial contentquality 0.84
Ultra-processed foods: Are they all bad for health?
Backs: “For instance, packaged whole grain breads, plant-based milks and some yogurts are considered ultra-processed, but they can be beneficial for health. Fortified cereals, for instance, have been instrumental in reducing the incidence of neural tube defects in infants due to the added folic acid.”